Condenser preheater



y 16, F. HODGKINSON l.721,251

CONDENSER PREHEATER Filed Nov. 27, 1926 F. 'H5cl9kinson lNVENTORATTORNEY WITNESSES Patented July 16, 1929.

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FRANCIS HODGKIN SON, OF SW'ARTHMORE, EENNSYLVANIA, ASSIGNOR TO WESTING-HOUSE ELECTBIO & MANUFACTURING COMPANY, A. CORPORATION OF PENNSYL-VANIA.

CONDENSER PREHEATER.

My invention relates to power plant apparatus and it has for an objectto provide means for preheating condensate to or near to the temperatureof exhaust steam.

A further object of my invention is to provide power plant apparatusincluding heatexchange devices or condensers arranged in series, bothreceiving exhaust steam from a prime mover, such as a turbine, thesurface condenser or heat exchange device condensing the major portionof the exhaust and discharging the condensate into the ct heat exchangedevice or condenser wherein the temperature of the condensate is raisedand a portion of the exhaust steam supplied to the jet heat exchangedevice or condenser is con densed.

In many condenser installations, condensate is discharged at atemperature much below that of the exhaust steam. This is particularlytrue of the vertical type condenser where.

the condensate trickles over a cold tube plate at the bottom.Accordingly, therefore, 1 provide a heating hotwell, or heat exchangedevice, into which condensate drains from the condenser by gravity andcomes into direct contact with a stream of exhaust steam, the exhauststeam serving to raise the temperature of the condensate and beingpartially condensed by the latter.

Another purpose of my invention is to provide a condenser of the typedesignated in which means are provided for withdrawing dissolved andnon-condensable gases from the condensate, either by raising thetemperature of the condensate, or by actually producing some degree ofevaporation. This is accomplished by providing means for reducing thepressure which would normally prevail within the hotwell.

These and other objects are effected by my invention as will be apparentfrom the following description andclaims taken in connection with theaccompanying drawings.

forming a part of this application, in which Fig. 1 is a view partiallyin section and partially in elevation showing my improvement applied toa vertical condenser installation; and I Fig. 2 is a view, partially insection, showing my improvement applied to a power in stallaton having ahorizontal condenser;

Fig. 3 is a partial view on a somewhat larger scale of the tubularmember 16 shown in Fig. 1.

Referring now to the drawings more in detail, in Fig. 1, I show aturbine having an exhaust end 10 from which steam is discharged throughsuitable passages 11 to vertical condensers 12'. Condensate drains fromthe bottoms of these condensers through suitable conduit connections 13to'my improved heat exchange device or heating hotwell at 14, whereinthe condensate has its tempera-v ture raised and the heating exhauststeam supplied thereto is partially condensed. This arrangement of heatexchange device or heating hotwell is particularly useful in connectionwith vertical condensers for the reason that condensate therein comes incontact with cold tube plates and thereby has its temperature lowered,causing a thermal loss.

Referring to the heat exchange device, heating condenser, or heatinghotwell at 14 more in detail, it will be seen that this device isprovided with an inlet chamber 15 for receiving condensate from theconduits 13, this condensate entering the concentric member 16 throughjet passages 17, the 'concentric m ember 16 having a convergent lowerdischarge portion 18 which depends within the receptacle 19 andcondensate is discharged through a suitable outlet 20. The upper end ofthe concentric tubular member 16 is open and communicates with the spaceor passage 22 leading to the exhaust chamber of the turbine. 7

It will, therefore, be seen that a stream-of exhaust steam passesdownwardly through the tubular member 16 and that jets of condensateenter such stream from the jet passages 17. In this way, the condensateis caused to present a high ratio of exposed surface to direct contactwith exhaust steam, thereby effecting exchange of heat from the steamtot-he condensate quite efliciently, resulting in the temperature of thecondensate being increased'and in a portion of the exhaust steam beingcondensed. In addition to the thorough inter-mixture of condensate andexhuast steam provided by the jets to promote heat exchange, thecondensate drains down in a sheet over the converging surface 18,thereby presenting further opportunity for direct contact of exhauststeam therewith to secure further heating andcondensation.

In order that a suitable draft may exist to assure the passage of thestream of exhaust steam through the member 16 in the manner referred toand in order that the effectiveness of the apparatus will not beimpaired by the accumulation of non-condensable gas coming from theexhaust of the turbine, I provide connections 23 leading to points inthe surface conoensers adjacent to the air offtalre portions of thecondensers and connected to the chamber 19 near to the top thereof.

Referring to the embodiment of my invention applied to a horizontalcondenser, in Fig. 2, I show a turbine 25 having an exhaust connection26 leading to a horizontal surface condenser 27, the latter beingprovided with suitable condensate outlet 28 and air and noncondensablegas offtalre 29. Condensate from the outlet 28 is supplied to the heatexchange device or hotwell, at 29, somewhat similar to the one alreadydescribed.

The heat exchange device, heating hotwell, or jet condenser at 29,receives oondensate from the heat exchange device or sur face condenser27 and exhaust steam by way of the conduit 30, which is connected to theexhaust connection 26, the heat exchange device heating hotwell or etcondenser at 29 serving to intermix the received media resulting in thetemperature of the condensate being increased and a portion of thereceived exhaust steam being condensed.

Referring to the heat exchange device, jet condenser, or heating hotwell29 more in detail, it will be seen that it comprises a receptacle 31having its upper end connected to the exhaust steam conduit 30 andhaving the condensate'outlet 28 entering through the top thereof anddepending therein. The lower end of the condensate outlet within thereceptacle has a convergent portion 82 having jet passages 33 arrangedto discharge condensate outwardly therefrom. Arranged below the outletof the conduit 30 and about and below the convergent jet passage portionof the condensate outlet 32, there is an inverted bellshaped orconvergent partition 34 connected circumferentially to the wall of thereceptacle and having an exit or throat portion 35 arranged below thelower end of the condensate outlet portion 32. Heated condensate isremoved through the outlet 36 from the lower portion of the receptacle81 by any suitable means not shown.

To assure the passage of a current of steam from the conduit 30 andthrough the converging passage provided by the member 34, I providemeans to effect a draft through these passages, or means to produce azone of lower pressure below the discharge end 35. To this end, I show aconduit 37 connected to the receptacle 31 above the throat portion 35and to the air and non-condensable gas offtake space 38 between thepartition 39 and the shell 4:0 of the condenser 27. In View of the factthat the pressure at the region where the conduit 37 enters thecondenser 27 is lower than that of the exhaust steam supplied to theconduit 30, and, for that matter, is also lower than the pressurecorresponding to the temperature of condensate entering the outlet 28,it is assured that a draft shall be -maintained tending to produce asuitable current of steam for the purpose stated and precluding theaccumulation of any non-condensable gas.

Furthermore, in the construction shown by Fig. 2, with connection 37admitted to condenser 27 at a point where the pressure is slightly lessthan at the connection 28, and because of the ample steam flow andintimate mixing, the condensate at 35 will be at a temperature higherthan that of evaporation at the pressure in the conduit 37, therebyproducing boiling or evaporation within the hotwell, and, consequently,deaeration and the withdrawal of dissolved gases.

From the foregoing, it will be apparent that I have devised anarrangement of heat exchange devices, one being of the surface type, andthe other being of the ct type, both devices receiving exhaust steamfrom a suitable prime mover, such as a steam turbine, and condensatefrom the surface heat exchange device beingsupplied to the jet heatexchange device, such condensate constituting the media of the jets andthe jet heat exchange device serving to increase the temperature ofcondensate and to condense some of the exhaust steam supplied thereto.More particularly, I have provideda heater hotwell which receivescondensate from a suitable condenser and raises its temperature bybringing exhaust steam into direct contact therewith. This arrangementof heater hotwell is particularly useful wherever the condensate of acondenser attains a temperature somewhat lower than the temperature ofexhaust steam, as is the case with a surface condenser of the verticaltype where the condensate trickles over cold tube plates or with conedensers of the simple down-flow type.

While I have shoWn my invention in several forms, it will be obvioustothose skilled in the art that it is not so limited, but is susceptibleof various other changes and modifications, without departing from thespirit thereof, and I desire, therefore, that only such limitationsshall be placed thereupon as are imposed by the prior art or as arespecifically set forth in the appended claims.

What I claim is:

1. In a power plant installation including a turbine and surfacecondensing means for condensing exhaust from the turbine, said surfacecondensing means having anoutlet for air and non-condensable gases, thecombination of heat exchanging means for effecting a heat transferbetween exhaustfrom the turbine and condensate discharged from thesurface condensing means, a direct connection between the turbineexhaust and said heat exchanging means, a direct connection between thecondensing compartment of the surface condensing means and said heatexchanging means, and means communicating with the surface condensingmeans in the vicinity of the air and non-condensable gas outlet thereoffor producing a pressurein said heat exchanging means below that of thetemperature of evaporation of the media therein.

2. In a power plant installation including a turbine and surfacecondensing means for condensing exhaust from the turbine, said surfacecondensing means having an outlet for air and non-condensable gases, thecombination of heat exchanging means for of fecting a heat transferbetween exhaust from the turbine and condensate discharged from thesurface condensing means, a direct con nection between the turbineexhaust and said heat exchanging means, a direct connection between thecondensing compartment of the surface condensing means and said heatexchanging means, and means associated with the surface condensing meansin the vicinity of the air and non-condensable gas outlet thereof forproducing a pressure in said heat exchanging means lower than the higherpressures in the surface condensing means.

3. In a power plant installation including a turbine and surfacecondensing means for condensing exhaust from the turbine, said surfacecondensing means having an outlet for air and non-condensable gases, thecombination of heat exchanging means for effecting a heat transferbetween exhaust from the turbine and condensate discharged from thesurface condensing means, a direct connection between the turbineexhaust and said heat exchanging means, a direct connection between thecondensing comparte ment of the surface condensing means and said heatexchanging means, and means for producing a pressure in said heatexchanging means corresponding approximately to that in the vicinity ofthe air and non-condensable gas outlet of the surface condensingmeansceive condensate from the surface condensing means, means forpassing steam directly from the turbine to the hotwell for heating thecondensate, and means for venting air and other non-condensable gasesfrom the hotwell to the surface condensing means in the vicinity of theair and non-condensable gas outlet of the latter.

5. In a power plant installation, including a turbine and surfacecondensing means for condensing exhaust. from the turbine, said surfacecondensing means having an outlet for air and other non-condensablegases, the combination of a hotwell, means for spraying condensate fromthe surface condensing means into the hotwell, means for passing steamdirect from the turbine into contact with the condensate in the hotwell,and means for venting air and non-condensable gases from the hotwell tothe surface condensing means in the vicinity of the air andnon-condensable gas outlet thereof.

In testimony whereof, I have hereunto sub-- scribed my name thisfifteenth day of November, 1926.

FRANCIS HODGKINSON

